A polarizing plate may be generally manufactured by laminating a tri acetate cellulose (TAC) film on both surfaces of a poly vinyl alcohol (PVA) film, attaching a protection film to the TAC film surface on any one surface to make a multi-structured polarizing film, and attaching a release film using an adhesive to a surface opposite to a surface where the protection film is formed.
Referring to FIG. 1, a multi-structured polarizing plate made by a stacking process as described above is conveyed after being cut to an optimum length through a cutting process, and before conveying the polarizing plate, inspection is performed to determine if impurities have been introduced into an adhesive layer.
That is, impurities may be introduced into an adhesive during an adhesive applying (coating) operation in the manufacture of the polarizing plate, and in this case, a spot defect may occur, and to detect the defect, an amount of light bleeding is measured with the same polarizing plate in a crossed position.
However, at this inspection stage, the release film attached to one surface of the polarizing film may reduce a degree of polarization of light, resulting in inaccurate inspection for impurities that may have been introduced.